A Dallas County jury deliberated for about two hours Tuesday before sentencing a 29-year-old woman to life in prison for sexually mutilating and fatally stabbing a man in 2012.

Cristal Richardson was found guilty Monday in the murder of Cedric Owens on April 28, 2012, at a Far East Dallas motel after a night of drinking alcohol and using drugs.

Prosecutors said Tuesday that Richardson has continued to exhibit violent behavior after her arrest in Owens' slaying. In the past six months, Richardson has attacked and threatened two Dallas County detention officers.

She punched one officer in the face in December after she refused to go into her jail cell. During a profanity-laced recorded phone call with a family member, Richardson described herself as a "maniac" and said she dragged the officer "out like a rag doll."

Richardson was previously convicted of aggravated assault with a deadly weapon in 2004 for stabbing someone during an argument, and she was convicted of driving while intoxicated with her son in the car in 2010.

Because of the previous convictions, Richardson faced an enhanced sentence.